JPS6350845B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a quench detection sensor for a superconducting coil.

Conventionally, this type of detector is shown in attached drawing No. 1.
I found something like the one shown in the picture.

That is, in the figure, numeral 1 is a superconducting coil, 2 is a voltage measurement line, 3 is a quench detector, L1 and L2 are the self-inductances of the 1a part and 1b part of the superconducting coil 1, and E1, E2 is self-inductance L1, L2
This shows the induced voltage caused by

Since the conventional device is configured like this,
When a current flows through the superconducting coil 1, induced voltages E1 and E2 are generated by the self-inductances L1 and L2.

In this case, if there is a voltage difference between the induced voltages E1 and E2, the higher induced voltage is divided by a resistor within the quench detector 3 to make it smaller, and both induced voltages E1 and E2 are reduced within the quench detector 3. Make the voltage difference at zero.

Under these conditions, the superconducting coil 1 is operated, but if the superconducting coil 1 quenches during excitation, resistance will initially occur in a part of the superconducting wire, so the voltage generated by that resistance will be reduced. , the quench detector 3 detects the occurrence of quench, thereby cutting off the coil current of the superconducting coil 1. In this way, superconducting coil 1
By interrupting the current of superconducting coil 1
This suppresses heat generation and prevents the superconducting coil 1 from burning out.

Since the conventional quench detector is configured as described above, if the quench occurs in the superconducting coil 1
occurs near the connection point with the central voltage measurement line 2a,
In addition, when the speed at which the quench spreads is the same in both parts 1a and 1b, the voltages E1 and E2 due to the resistance generated in parts 1a and 1b are also the same, and therefore the difference between voltages E1 and E2 is also close to zero. As a result, it may become impossible for the quench detector 3 to detect the quench. Therefore, superconducting coil 1
There were drawbacks such as the fact that the occurrence of quench was overlooked in the process, and the superconducting coil 3 could be burnt out.

The detection sensor of the present invention eliminates the shortcomings of conventional devices, and provides reliable quench detection for superconducting coils that reliably detects the occurrence of quench and protects the superconducting coil from burning out. Its purpose is to provide sensors.

In order to achieve this object, the present invention provides a superconducting element wire that is closely attached to a superconducting wire wound around a superconducting coil and has a current carrying wire and a voltage measuring wire connected to both ends of the superconducting wire; The superconducting wire is characterized in that it is comprised of a voltage detector connected to a voltage measurement line to detect the generated voltage based on the electrical resistance generated in the superconducting element wire.

Hereinafter, the present invention will be explained based on the attached drawing, FIG. 2, which shows one embodiment of the present invention.

In the figure, numeral 11 is a superconducting wire constituting a superconducting coil, and 12 is a superconducting wire 11.
A superconducting wire 12 is attached in close contact with the superconducting wire 12, and current-carrying wires 13 for passing a predetermined current through the superconducting wire 12 are connected to both ends of the superconducting wire 12.
A voltage measurement line 14 is connected to a voltage detector (not shown) that detects the voltage generated by the electrical resistance generated in the superconducting wire 12.
Note that the close contact of the superconducting wire to the superconducting wire is achieved by placing the current carrying wire 13 and the voltage measuring wire 1 on the surface of the superconducting wire 11.
This is done by pasting the superconducting strands 12 connected to 4 so that no induction occurs.
Further, the current flowing through the current-carrying wire 13 is a current that is sufficiently smaller than the critical current of the superconducting wire 12 .

The quench detection sensor of the present invention is constructed as described above, and its operation will be explained next. First, as mentioned above, a small current is passed through the current-carrying wire 13, but under normal conditions, since both the superconducting wire 11 and the superconducting strand 12 are at low temperatures, no resistance is generated in the superconducting strand 12. Therefore, no voltage is generated across the superconducting wire 12, and as a result, no voltage is detected by a voltage detector (not shown).

However, once the superconducting coil quenches and the surface temperature of the superconducting wire 11 rises, and the temperature of the superconducting wire 12 in close contact with the superconducting wire 11 exceeds its critical temperature, the superconducting wire 12 has no resistance. occurs and a voltage appears across it due to its resistance. Therefore, by guiding this generated voltage to the voltage detector through the voltage measurement line 14, the occurrence of quench in the superconducting coil can be reliably detected by the display on the voltage detector. This cuts off the power supply to the superconducting coil, thereby reliably preventing burnout of the superconducting coil due to excessive heat generation of the superconducting coil.

The quench detection sensor of the present invention is constructed and operates as described above, but instead of attaching the superconducting wire 12 directly to the superconducting wire 11, as shown in FIG. 21
The superconducting strands 12 may be covered with a superconducting wire to protect the superconducting strands 12 from external mechanical forces, and as a result, the additional effect of making it easier to attach the superconducting strands 12 to the superconducting wires 11 occurs. do.

Since the quench detection sensor of the present invention is configured and operates as described above, it always reliably detects quench no matter where quench occurs in the superconducting coil, thereby preventing burnout of the superconducting coil. This has the effect of making it possible to provide a highly reliable quench detection sensor.

[Brief explanation of the drawing]

FIG. 1 is a schematic circuit diagram of an example of a conventional quench detection device for a superconducting coil, FIG. 2 is a schematic circuit diagram of an embodiment of a quench detection sensor of the present invention, and FIG. 3 is a schematic diagram of an example of a quench detection sensor of the present invention. FIG. 2 is a perspective view schematically illustrating the main parts of the embodiment. 1...Superconducting coil, 2,14...Voltage measurement wire, 1
DESCRIPTION OF SYMBOLS 1... Superconducting wire, 12... Superconducting wire, 13... Current carrying wire, 21... Electric insulator. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. A superconducting element wire that is closely attached to a superconducting wire wound around a superconducting coil and has a current carrying wire and a voltage measuring wire connected to both ends thereof, respectively, and is connected to the voltage measuring wire. and a voltage detector for detecting a generated voltage based on the electrical resistance generated in the superconducting wire. 2. A quench detection sensor for a superconducting coil according to claim 1, wherein the superconducting wire is covered with an insulation material.